Although archeologists have been pushing the date back further, the last I heard we have been around since 250,000 BCE.

Some in the Mormon Church speculate that these were the Pre-Adamic peoples. Adam and Eve happened and their descendant intermarried with the Pre-Adamites and that would account for why only Pre-Adamic DNA is found in today's population.

So where was the birthplace of Mankind? Well, we sort of have three:

1. The Fertile Crescent area of the Bible2. Adam-ondi-Ahman from the Joseph Smith Missouri trek.3. The Plains of the Serengeti in Africa for the rest of Mankind.

Question - Are the first two less valid than the third?

Answer - No, creation stories have their own validity as part of our rich oral and written religious traditions. Consider the beautiful poetic creation narrative found in the Finnish Kalevala, Birth of Wainamoinen:

In primeval times, a maiden,Beauteous Daughter of the Ether,Passed for ages her existenceIn the great expanse of heaven,O'er the prairies yet enfolded.Wearisome the maiden growing,Her existence sad and hopeless,Thus alone to live for agesIn the infinite expansesOf the air above the sea-foam,In the far outstretching spaces,...